Cylinder casting or cylinder block for steam engines and the like



June 3, 1941. J HQY 2 243364 CYLINDER CASTING OR CYLINDER BLOCK FORSTEAM ENGINES AND THE LIKE File'd Sept. 20, 1939 4 Sheets-Sheet l T.J/HOY CYLINDER CASTING 0R CYLINDER BLOCK FOR STEAM ENGINES AND THE LIKE-ed Sept. 20, 1939 4 Sheets-Sheet 2 June 3, 1941. J HQY CYLINDER CASTING0E CYLINDER BLOCK FOR STEAM ENGINES AND THE LIKE 4 Sheets-Sheet 3 FiledSept 20, 1939 June 3, 1941. J, HOY 2,243,864

CYLINDER CASTING OR CYLINDER BLOCK FOR STEAM ENGINES AND THE LIKE FiiedSept. 20, 1959 4 Sheets-Sheet 4 Patented June 3, 1941 CYLINDER CASTINGOI CYLINDER BLOCK FOB STEAM ENGINES AND m m Thomas J. Roy, Newark, N. I.Application September a, 1939, serial No. seam scum. (Cl. izi-iss) IThis invention relates to improvements in the cylinder valve chest andvalve cage construction of steam drivenlocomotive engines or the like,

in which thedistributlon of the steam is effected under the control ofcm operated poppet Fig. 6 represents an enlarged detailed view oi thepoppet valve, cage for an inlet poppet valve.

7 represents a detailed view of the valve cage for an exhaustpoppetvalve.

valves which may be of the balanced or double seat type. c i v i c Aprimary object of the invention is to provide thrust or other internalstresses due to unequal expansionof the metal under the influence oftemperature differentials. With this obiect in view. the invention isparticularly useful in high Such distori means to obtain true valveseatings to ensure} capacity locomotives utilizing steam at highpi'essures with a high degree of superheat, in which a steam tightpoppet valve isessential.

Another object of the invention is to provide mechanism to attain theforegoing advantages,

which shall be positive in operation, simple in construction. andreadily applicable to o tional locomotives.

How I attain the foregoing, together with such other objects andadvantages as areincident to my invention or will occur to those skilledin the art, will appear .from the following description taken togetherwith the accompanying drawings. in which:

Fig. 3.represents a longitudinal section on verinto the power cylinders.

. Fig. 4 represents a longitudinalsectionon vertical plane through thecenter of the exhaust port which connects the power cylinderthrough theexhaust passages with the exhaust nozzle in the smoke box.

Fig. 5 represents a section following a horizontal pl'anethrough thesteam chest which is provided with a common branch pipe leading from thesource vof supply of live steam to the power cylinders.

chest Similar reference numbers indicate corresponding partsthroughoutthe views in the drawings.

Referringnow to the drawings in detail it will,

be seen that for each power cylinder, two inlet poppet valves and twoexhaust Poppet valves are provided. Live steam is admitted throughbranch pipe H into cavities i and l, whence it flows into the powercylinder. After having done its work the live steam escapes throughcavity 3 to the exhaust poppet. valve and then to passages O. whence itflows to the base of the exhaust nos-e zle II. It should be noted thatthe poppet valve can be preferably constructed along the lines of thedesign disclosed by the inventcrs patent application bearing Serial No.291,806,. dated August 25, 1938. However, the scope of thisim vention isnot limited to this type of poppet valve and the conventional styles canalso be used. Experience with known type of poppet valve 081- inders hasshown that it is not always possible to maintain the trueness of thevalve seatlngs, v

if the same are rigidly attached to the cylinder structure. Not only aresuch valve seatings likely to become distorted under the influence ofuneven expansion within the cylinder casting but they also have atendency to change their relative positions when comparedwlth theconditions which prevail when the valves are ground in at first.Moreover, experience with a heavily pulling steam locomotive of theconventional design has shown a tendency to a certain amount oibreathing within the cylinders and surround ing bed plates due to theperiodical fluctuations of the piston thrust.

It is therefore obvious that valve seatings whlch are rigidly attachedto the cylinder structure must inevitably become affected by suchperiodlcal breathing movements and steam tighttical plane through thecenter of the inlet steam port through which the live steam is admittedness is dii'ncult under such conditions.

By referring now to Fig. 6 it will be seen that f according to the newinvention, the following means eliminate the aforementionedinconveniences. Instead of havinga valve cage rigidly fastened to themain cylinder structure according to conventional and known poppet valvecylinder designs, in my new invention resilient means are interposedbetween the valve cages and the cylinder structure. The valve cage 2!contains a double seat poppet valve arrangement is preferably madespherical to facilitate alignment and the same is connected to inletvalve cage 29 by means of ring 30, which in turn is held in po sition byseveral flat-headed screws and fluid tightness is obtained by means of agasket 31.

The connection between part 36 and part 30 is Since it is necessary toprovide a fluid pressure tight seal between cavity 5 and cavity 4, whenthe poppet valve is in position, it is likewise essential that such aseal should be of a resilient character. Accordingly, a metallic bellowsof the type 34 is interposed between the upper part of the valve cage 29and the cylinder structure; This bellows 34 is welded in'a fluidpressure tight manner on one of its extreme ends to valve cage 29 and onthe other extreme end torestraining ring 33, which is pressed against aresilient gasket 28 in a fluid pressure tight manner and which isfastened to the cylinder structure by several cap screws 32. v

It will no 'doube be clear from the foregoing description that a changein shape of the cylinder structure, within reasonable limits, will notaffect the trueness in relationship to the center bore of valve stemguide 25 of valve seats and 36,- since the flexible bellows 34 and thegaskets 3| and 28 are not capable of transmitting any distorting forcesto the valve cage structure 29. Moreover, as will be noted from Fig. 6,the diameter of the cylindrical extension of valve cage- 29 projectinginto a corresponding bore in the cylinder structure is purposely keptsmaller so as to render immune said valve cage against structuraldeformation of the cylinder.

To satisfy requirements of ease of inspection and removal, the cylinderstructure is provided with a steam chest shaped to be free fromobstructions on its top as will be seen in Figs. 1, 2

and 3. Suitable circular openings 6, which are located directly abovethe recess for the reception of inlet valve cage 29, render the problemof periodical examination of the poppet valve assembly an easy one, asall thatis necessary, is to remove the inspection cover, (not shown),which is fastened in a steam tight manner to the top of the steam chest5. Incidental to the construction as is disclosed by Fig. 6, anotheradvantage is also obtained. The direction of flow of live steam fromsteam chest 5 to the power cylinder through cavity 4 is made free fromsharp bends and streamlined flow of the live steam is almost possible.The valve cage 29 is provided with bridges of a comparatively smallcross sectional area to impede as little as possible the flow of steam.In contrast to conventional valve cage construction in which aconsiderable force has to be transmitted through such bridges to effecta steam tight valve cage, in my invention no such need exists, since theonly force which tends to pull the top part of the valve cage from thebottom part of the same is the axial resistance of the bellows 34, whichnaturally is negligible in comparison with the tensile and compressionstrength of the valve cage bridges. Under such conditions, the wiredrawin losses of the live steam will be reduced considerably and a gainin cylinder efiiciency can be expected. 'As will be noted from Figs. 1and 6, and Fig. 3 in particular, my new invention also lends itselfparticularly well to an easy machining operation as no close tolerancesare required for the recesses which are provided for the valve cages 29.Furthermore, the problem of maintenance by roundhouse mechanics of adevice built according to my invention is greatly simplified in contrastwith the problem presented by known poppet valve gear designs, becauseafter removal of the valve cage 29 from the cylinder structure, the

wholeassembly can be cleaned and repaired on a working bench in theroundhouse without the need of working on a more or less inaccessiblecylinder block of a locomotive, which more often than not, is exposed toinclement weather conditions in the yard.

In the event of failure of a part of the valve cage assembly, a spareassembly, which may be kept in the store room, can be readily put in theplace of the defective assembly without the need of fitting Worknecessitating the use of skilled mechanics, because the flexibility ofthe gasket 3| and bellows 34 and 38will compensate for any inaccuraciesof assembly.

Adhering to the principle of greatest freedom in the flow of the steam,my new invention also provides a novel method of construction of thevalve cages for the exhaust poppet valve. By referring to Fig. 7, itwill be seen that in accordance with the aforesaid principle, theexhaust valve cage is inverted by comparison with the construction ofthe inlet poppet valve cage as shown by Fig. 6. Whereasthe flow of thesteam from the steam chest 5 into cavity 4, leading into the powercylinder is downward, the flow of' the exhaust steam from the powercylinder through port 3 into cavity 8 which leads to the base of theexhaust nozzle i0, is taking place in an upward direction. Consequently,the whole exhaust valve cage assembly will have to be withdrawn throughaperture 1 in Figs. 1 and 4 becauseno part thereof can be fastened tothe partition wall 9 in the absence of suitable space. Here again theresilient means employed to effeet a pressure tight seal between cavity3 and 8 are similar to the ones used in the case of the inlet valve cageassembly shown by Fig. 6.

Resilient means of a similar character are employed for the exhaustpoppet valves as shown on Fig. 7. Exhaust valve cage I2 is extendingthrough aperture 1 into recess 9 of the exhaust port 3. Again it will benoted that the exhaust valve cage I2 is kept to a smaller diameter onits top portion by comparison with the corresponding aperture 1. Anelastic packing I8 establishes a steam tight seal of the exhaust cavity8 against the atmosphere. It will be evident that slight variations inshape of the cylinder structure are not likely to cause any deformationsof the exhaust valve cage l2 because the elastic packing l8 will'absorbany such irregularity. In

order to establish a steam tight seal between the exhaust port 3 and thecavity 8 when the exhaust valve is in position, resilient means areagain employed to render the exhaust valve vage immune against anypossible distortions which may take place within the cylinder structure.In the described conception of my invention, metallic bellows I! whichare welded in a fluid pressure tight manner to the valve cage l2 on oneextreme end and to a retaining ring l5 on the other extreme end, willserve the purpose.

The retaining ring II in turn is pressed against gasket I! so as toprevent the escape of pressure steam from port 3 into cavity 8. With theview oi iacilitating removal oi. the whole assembly ior' inspectionpurposes. a specially designed tightening rod 20, which can be grippedfrom the outside on its top extension with a wrench,

is provided. A cap is which is provided with a, pipe thread is screwedinto a corresponding resees in the top flange oi the valve cage "toprevent any leakage of exhaust steam. Several tightening rods II,equally spaced, will make the problem oi maintaining a. steam tightvalve case seal against the cylinder structure easy and no matter howcarelessly these rods may be tightened, no crushing of the valve cagebridges will take place by contrast with the known methods of attachmentof such valve cages to their respective cylinder structures. Fig. 7 alsodiscloses the same style 01' valve seat attachment ior the sphericalvalve seat it as has been employed in the inlet valve cage construction.The restraining plate 22, in conjunction with metallic bellows 2|,functions in a manner already disclosed by my invention in accordancewith the specifications bearing Serial No. 291,806, dated August 25,1939 in the event or a double seat poppet valve construction beingadopted. Adaptof the double seat type, comprising inlet poppet valvecages and exhaust poppet valve cages. said cages being attached in aresiliently steam tight manner to the surrounding parts of the cylinderstructure through metallic bellows and detachable retaining rings topermit removal of said poppet valve cages together with said resilienter piece It and valve stem guide ll again have the same purpose asdisclosed by the embodiment of my invention shown on Fig 6. The valveseat II, closest to the power cylinder, is preferably flat and part ofthe valve cage II. It is understood that the scope or this invention isnot limited to the specific resilient means shown in this instance torender the valve case I! immune against deformations in the cylinderstructure but covers also mechanical equivalents to the constructiondescribed. 1,

I claim:

'1. In cylinder structure for t"- ion of power to the main drivingwheels of steam locomotives or the like, or the character described, inwhich the distribution of the steam is eiiected under the control of camoperated poppet valves of the double seat type, comprising inlet p ppetvalve cages and exhaust pop t valve cages for each power cylinder. meansto render such valve cages immune against distortions within thecylinder structure.

2. In cylinder structure for transmission of power to the main drivingwheels of steam locomotives or the like, oi the character described, inwhich the distribution of the steam is eii'eoted under the control ofcam operated poppet valves 01' the double seat type, comprising inletpoppet valve cages and exhaust poppet valve cages for inder structin'e,said means being attached in a fluid pressure tight manner to the valvecages and the power cylinder structure respectively.

means irom the cylinder structure in one unit.

5. In cylinder structure for transmission 0! power to the main drivingwheels of steam locomotives or the like, oi the character described. inwhich the distribution of steam is eiiected under the control of camoperated popp Wives of the balanced, or nearly balanced type, comprisinginlet poppet valve cages and exhaust poppet valve cages tor each powercylinder, means to render such valve cases immune against distortionswithin the cylinder structure.

6. In cylinder structure tor transmission of power to the main drivingwheels 01' steam looomotives or the like, or the character described, inwhich the distribution oi steam is eflected under the control of camoperated po pet valvesoi the balanced or nearly balanced type,comprismotives or the like, in which the distribution of steam isenacted under the controioi cam operated poppet valves of the balanced-or nearly balanced type, comprising inlet poppet valve cagesand exhaustpoppet valve cages for each cylinder, means to render such valve cages m,mune against distortions within the cylinder structure,said meansconsisting of metallicbel lows.

8. In cylinder structure for. transmission'oi 3 power to the maindriving wheels or steam locoeach powercylinder, means to render sumvalve cages immune against distortions within the cyl- 3. In cylinderstructure for transmission of power to the main driving wheels oi steamlocomotives or the like, oi the character described,

in which the distribution oi the steam is eii'ected under the control ofcan operated po pet valves or the double-seat type,

" inlet motives or the like. oi the character described, in

which theoistribution or steam is elected under the control of camoperated'poppet valves oi the balanced or nearly balanced type,comprising inlet poppet valve cages and exhaust poppet valve cages, saidcages being attached in a resilient and steam tight manner to thesurrounding parts of the cylinder structure by means of metallic bellowsand detachable retaining rings to permit removal oi said poppet valvecages'together with said poppet valve cages and said resilient meansfrom the cylinder structure.

THOMAS J. 30?.

